The United States and more than 100 other signers of the 1968 nuclear Nonproliferation Treaty (NPT) are to review the treaty in Geneva next Aug. 11 -Sept. 5. They will seek to determine whether there is still any prospect of confining nuclear arms development to the five original nuclear states: the US, USSR, Britain, France, and China.

More and more states are producing "peaceful" nuclear materials, the independent Stockholm International Peace Research Institute (SIPRI) reports in its annual armaments book released June 12.

A total of 100,000 kilograms of unprocessed plutonium, a byproduct of power generation and a prime raw material for weapons, "has been accumulated from civilian nuclear reactors," the SIPRI World Armament and Disarmament Yearbook reports. About 230 reactors generating about 120,000 megawatts of electricity (MWE) in 22 countries will be augmented by about 230 more reactors under construction.

By the year 2000, says SIPRI, operational reactors generating 600,000 MWE will be producing about 250,000 kilograms of plutonium annually -- enough to make about 50,000 bombs of the type the US used to destroy Nagasaki, Japan, in 1945.

The biggest such reprocessing facility in Asia and one of the third world's largest is contained in two 200-MWE reactors at India's Tarapur nuclear power station, south of Bombay. The General Electric and Bechtel corporations of the US built them, partly with a US aid loan of $80 million. The reactor was almost identical with one built in northern Illinois for Commonwealth Edison by the same US team.

Besides Tarapur, India operates other nuclear installations not subject to International Atomic Energy Agency "full scope" or other international safeguards against use for military purposes at Apsara, Cirus, Purnima, Trombay, and Hyderabad. India successfully tested a nuclear explosive in 1974.

In Pakistan, US nuclear-proliferation experts say, a pilot uranium enrichment plant and laboratory at Kahuta, near Islamabad, an area "off limits" to foreign diplomats (the French ambassador to Pakistan was beaten up by thugs when he apparently came too close), are outside safeguards applied to other Pakistani installations.

Western analysts believe a Pakistani test explosion, using uranium enriched with technology obtained mainly in Western Europe, may be only months away.

Other unsafeguarded, or "doubtful" nuclear facilities outside the five "nuclear club" states include Egypt's old Soviet-supplied research reactor at Inshass; Israel's Dimona research reactor and nearby reprocessing and heavy-water plants (which the CIA and many other sources have said have nuclear- weapons capability), and South Africa's pilot enrichment plant built with West German help at Valindaba.

There is also a power reactor operated jointly with France, at Vandellos, Spain, and the prospect of similarly unsafeguarded installations, now under construction or contracted for, in Argentina, Brazil, and South Korea. Taiwan's considerable nuclear-power installations were put under safeguards earlier, after indications of a possible Taiwanese nuclear-weapons research program.

Col. Muammar al-Qaddafi's Libyan government has made deals with the Soviet Union to buy two Soviet research and power reactors. However, US experts say, the Soviets generally impose severe safeguard controls when they export nuclear technology. Contrary to published Western reports, they add, Pakistan has almost certainly not shared its nuclear technology with Libya for production of an "Islamic" nuclear bomb.

Both Libya and Pakistan, however, are either already obtaining, or are actively seeking, to purchase uranium from the subSaharan African state of Niger. Libyan troops occupy a mineral-rich strip of Libya's southern neighbor Chad, believed to contain uranium, and Libya is backing one of the factions in Chad's civil war.

The US Nuclear Regulatory Commission (NRC) must pass on each delivery of US nuclear fuel abroad. On May 16 it unanimously rejected India's application to buy 38 more tons of highly enriched uranium for Tarapur. Congressmen and scientists who support the NRC rejection argue that until India and other "threshold" states accept full international safeguards and inspection, the US administration should live up to President Carter's 1977 guidelines against export of US nuclear technology to them.

A counter-argument, heard in the administration and which President Carter may use if he overrides the NRC, is that denial of the US fuel would not prevent the Indians from getting it elsewhere, including the USSR, or further pursuing weapons research. Granting it, they add, would keep alive the Indian-US nuclear accord and so keep the small leverage the US may still have.